Donal--I'll give the points to you.

The point of this question was as follows.

If you travel a path where all other factors
are constant, and you do not return to your
starting point, something external force is
acting on your boat. That force is called
current, although it could be wind or
anything else--a barnacle on one side of
your bottom. Anything that you can't
explain is attributed to current.

I apologize if the question was too
vague.



Donal wrote

"Bart Senior" wrote

You sail directly East for 14 hours,
then South for 14 hours,
and then West for 14 hours,
and then North again for 14 hours.

Now if you draw a vector between your starting
position and your final position. What would you
call that vector?

A Tidal vector.

Donal